diff options
Diffstat (limited to 'kernel/arch/powerpc/sysdev/scom.c')
| -rw-r--r-- | kernel/arch/powerpc/sysdev/scom.c | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/kernel/arch/powerpc/sysdev/scom.c b/kernel/arch/powerpc/sysdev/scom.c new file mode 100644 index 000000000..6f5a8d177 --- /dev/null +++ b/kernel/arch/powerpc/sysdev/scom.c @@ -0,0 +1,236 @@ +/* + * Copyright 2010 Benjamin Herrenschmidt, IBM Corp + * <benh@kernel.crashing.org> + * and David Gibson, IBM Corporation. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See + * the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <linux/kernel.h> +#include <linux/debugfs.h> +#include <linux/slab.h> +#include <linux/export.h> +#include <asm/debug.h> +#include <asm/prom.h> +#include <asm/scom.h> +#include <asm/uaccess.h> + +const struct scom_controller *scom_controller; +EXPORT_SYMBOL_GPL(scom_controller); + +struct device_node *scom_find_parent(struct device_node *node) +{ + struct device_node *par, *tmp; + const u32 *p; + + for (par = of_node_get(node); par;) { + if (of_get_property(par, "scom-controller", NULL)) + break; + p = of_get_property(par, "scom-parent", NULL); + tmp = par; + if (p == NULL) + par = of_get_parent(par); + else + par = of_find_node_by_phandle(*p); + of_node_put(tmp); + } + return par; +} +EXPORT_SYMBOL_GPL(scom_find_parent); + +scom_map_t scom_map_device(struct device_node *dev, int index) +{ + struct device_node *parent; + unsigned int cells, size; + const __be32 *prop, *sprop; + u64 reg, cnt; + scom_map_t ret; + + parent = scom_find_parent(dev); + + if (parent == NULL) + return 0; + + /* + * We support "scom-reg" properties for adding scom registers + * to a random device-tree node with an explicit scom-parent + * + * We also support the simple "reg" property if the device is + * a direct child of a scom controller. + * + * In case both exist, "scom-reg" takes precedence. + */ + prop = of_get_property(dev, "scom-reg", &size); + sprop = of_get_property(parent, "#scom-cells", NULL); + if (!prop && parent == dev->parent) { + prop = of_get_property(dev, "reg", &size); + sprop = of_get_property(parent, "#address-cells", NULL); + } + if (!prop) + return NULL; + cells = sprop ? be32_to_cpup(sprop) : 1; + size >>= 2; + + if (index >= (size / (2*cells))) + return 0; + + reg = of_read_number(&prop[index * cells * 2], cells); + cnt = of_read_number(&prop[index * cells * 2 + cells], cells); + + ret = scom_map(parent, reg, cnt); + of_node_put(parent); + + return ret; +} +EXPORT_SYMBOL_GPL(scom_map_device); + +#ifdef CONFIG_SCOM_DEBUGFS +struct scom_debug_entry { + struct device_node *dn; + struct debugfs_blob_wrapper path; + char name[16]; +}; + +static ssize_t scom_debug_read(struct file *filp, char __user *ubuf, + size_t count, loff_t *ppos) +{ + struct scom_debug_entry *ent = filp->private_data; + u64 __user *ubuf64 = (u64 __user *)ubuf; + loff_t off = *ppos; + ssize_t done = 0; + u64 reg, reg_cnt, val; + scom_map_t map; + int rc; + + if (off < 0 || (off & 7) || (count & 7)) + return -EINVAL; + reg = off >> 3; + reg_cnt = count >> 3; + + map = scom_map(ent->dn, reg, reg_cnt); + if (!scom_map_ok(map)) + return -ENXIO; + + for (reg = 0; reg < reg_cnt; reg++) { + rc = scom_read(map, reg, &val); + if (!rc) + rc = put_user(val, ubuf64); + if (rc) { + if (!done) + done = rc; + break; + } + ubuf64++; + *ppos += 8; + done += 8; + } + scom_unmap(map); + return done; +} + +static ssize_t scom_debug_write(struct file* filp, const char __user *ubuf, + size_t count, loff_t *ppos) +{ + struct scom_debug_entry *ent = filp->private_data; + u64 __user *ubuf64 = (u64 __user *)ubuf; + loff_t off = *ppos; + ssize_t done = 0; + u64 reg, reg_cnt, val; + scom_map_t map; + int rc; + + if (off < 0 || (off & 7) || (count & 7)) + return -EINVAL; + reg = off >> 3; + reg_cnt = count >> 3; + + map = scom_map(ent->dn, reg, reg_cnt); + if (!scom_map_ok(map)) + return -ENXIO; + + for (reg = 0; reg < reg_cnt; reg++) { + rc = get_user(val, ubuf64); + if (!rc) + rc = scom_write(map, reg, val); + if (rc) { + if (!done) + done = rc; + break; + } + ubuf64++; + done += 8; + } + scom_unmap(map); + return done; +} + +static const struct file_operations scom_debug_fops = { + .read = scom_debug_read, + .write = scom_debug_write, + .open = simple_open, + .llseek = default_llseek, +}; + +static int scom_debug_init_one(struct dentry *root, struct device_node *dn, + int i) +{ + struct scom_debug_entry *ent; + struct dentry *dir; + + ent = kzalloc(sizeof(*ent), GFP_KERNEL); + if (!ent) + return -ENOMEM; + + ent->dn = of_node_get(dn); + snprintf(ent->name, 16, "%08x", i); + ent->path.data = (void*) dn->full_name; + ent->path.size = strlen(dn->full_name); + + dir = debugfs_create_dir(ent->name, root); + if (!dir) { + of_node_put(dn); + kfree(ent); + return -1; + } + + debugfs_create_blob("devspec", 0400, dir, &ent->path); + debugfs_create_file("access", 0600, dir, ent, &scom_debug_fops); + + return 0; +} + +static int scom_debug_init(void) +{ + struct device_node *dn; + struct dentry *root; + int i, rc; + + root = debugfs_create_dir("scom", powerpc_debugfs_root); + if (!root) + return -1; + + i = rc = 0; + for_each_node_with_property(dn, "scom-controller") { + int id = of_get_ibm_chip_id(dn); + if (id == -1) + id = i; + rc |= scom_debug_init_one(root, dn, id); + i++; + } + + return rc; +} +device_initcall(scom_debug_init); +#endif /* CONFIG_SCOM_DEBUGFS */ |